Moisture-curing compositions based on silane-functional polymers are known and are used among other things as elastic adhesives, sealants, and coatings. They are free from isocyanate groups and therefore constitute an alternative, one preferred from a toxicological standpoint, to the isocyanate-containing polyurethane systems.
For the majority of these applications, as a sealant or as an assembly adhesive, for example, it is critical that the compositions cure rapidly and in the cured state possess good mechanical properties and good adhesion properties. Particularly important is a combination of extensibility and high tensile strength. However, such compositions often fail to satisfy these requirements.
The use of organoalkoxysilanes as additives in moisture-curing compositions based on silane-functional polymers is known. They are typically used in order to tweak properties such as adhesion, storage stability, and reactivity, as is described, for example, in U.S. Pat. No. 3,979,344, and No. 5,147,927, and EP 0 819 749 A1.
U.S. Pat. No. 6,703,453 discloses moisture-curing compositions based on silane-functional polymers which include, among other constituents, an adduct of an aminosilane and maleic or fumaric esters. The compositions are said to exhibit improved mechanical properties and an improved storage stability.